Light metal alloy



lotented Apr. 19, 1932 All UNITED PATENT OFFICE PERCY PRITGHARD, OISME'EHWICK, NEAR BIRMINGHAM, ENGLAND, ASSIGNOR, BY

MEQNE ASSIGNMENTS, T0 ALUMINUM. COMPANY 0]! AMERICA, OF PITTSBURGH,

PENNSYLVANIA, .A. CORPORATION OF PENNSYLVANIA LIGHT METAL ALLOY NoDrawing. Application filed January 31, 1931, Serial No. 512,745, and inGreat Britain ljebruai'y 7, 1930.

The object of the present invention is to provide an aluminium andsilicon alloy having improved physical and casting properties.

Accordingly our improved alloy consists of an aluminium silicon alloy inwhich the silicon content is from 8 to 13% to which is added nickel inan amount equal to A, to 3%% of the total content. These percentages areby weight.

The preferred proportions are three per cent nickel, eleven per centsilicon and the remainder aluminium.

In a convenient manufacture we first make an aluminium silicon alloywith a 13% silicon content and make an alloy of aluminium and nickelwith a 20% nickel content.

We take 85 pounds of the former and 15 pounds of the latter which whenmelted together gives the preferred proportions inicated above.

We find the tensile strength of this alloy is considerably greater thanthat of ordinary aluminium silicon alloy, whilst its ductilit iseminently satisfactory. Further, its yield oint is raised; its hardnessis increased and its machining properties which are usually poor insilicon alloys are remarkably improved.

The casting properties of the alloy are also much better; chilling,generally speakmg5 being entirely eliminated. he alloy lends itself verywell to the well .known modification process by means of metallic sodiumor sodium of salts whereby a coarse structure can be converted to a finegrain silky one. Y

I claim 1. An improved light metal alloy containing by weight 86% ofaluminium, 11% of silicon and 3% of nickel.- 2. An alloy consisting of0.5 to 3.5 per 1 cent of nickel, 8.0 to 13.0 per cent of silicon,

' the balance being aluminium.

.- Intestimony whereof I afiix my signature. PERCY PRITCHARD.

